Quick answer: The Microsoft Japan four-day workweek experiment closed the company’s offices on all five Fridays in August 2019 and gave permanent employees special paid leave. Sales per employee were 39.9% higher than in August 2018, while electricity use fell 23.1% and printing fell 58.7%. Microsoft later cautioned that the sales increase reflected several factors and should not be credited to the four-day-week trial alone.
In August 2019, Microsoft conducted a remarkable experiment in Japan, giving approximately 2,300 employees five Fridays off while continuing to pay them their usual salaries.
As a result, employees worked only four days a week during that month, instead of five.
But the experiment wasn’t limited to simply granting an extra day off.
At the same time, the company encouraged employees to hold shorter meetings, reduce unnecessary emails, and find more efficient ways to get work done.
By the end of the experiment, productivity—measured by sales per employee—had increased by about 40% compared to the same month the previous year.
Important context: The 39.9% figure is real, but Microsoft later moved it out of the trial’s direct-results section. The company said sales per employee were affected by several factors, so the trial cannot be treated as the sole cause of the increase.
The company also recorded a decrease in electricity consumption, and far fewer pages were printed during the trial period.
The idea was not for employees to cram five days’ worth of work into four days; rather, the experiment aimed to rethink the time that might be wasted on long meetings, unnecessary correspondence, and inefficient work routines.
However, the experiment lasted only one month, so it did not prove that all companies would achieve the same results when implementing a 4-day workweek.
Nevertheless, the experiment called into question one of the oldest assumptions about work:
Spending more time in the office does not always mean getting more work done.
Microsoft Japan four-day workweek: key results
- Schedule: Microsoft Japan closed its offices on all five Fridays in August 2019 and gave permanent employees special paid leave.
- Sales per employee: Up 39.9% compared with August 2018. Microsoft said multiple factors influenced this figure, so it is not proof that the shorter week alone caused the increase.
- Employee response: 92.1% of surveyed employees approved of the four-day-week and three-day-weekend arrangement.
- Resource use: Electricity consumption fell 23.1%, while printed pages fell 58.7%; both were compared with August 2016.
- Main limitation: The program lasted one month and did not use a randomized control group.
What the Microsoft Japan four-day workweek tested
Microsoft Japan called the program the “Work-Life Choice Challenge Summer 2019.” Every Friday in August, on August 2, 9, 16, 23, and 30, became a company holiday. Permanent employees received special paid leave, and the company’s offices closed.
The shorter week came with changes to daily work. Employees were urged to replace some meetings with chat, use online meetings more often, and aim for 30-minute meetings. Microsoft used Teams and Workplace Analytics to examine how people communicated and worked during the test.
Microsoft Japan four-day workweek results at a glance
Microsoft compared several August 2019 measures with earlier periods:
| Measure | Reported change | Comparison period |
|---|---|---|
| Sales per employee | +39.9% | August 2018 |
| Working days | -25.4% | August 2018 |
| Printed pages | -58.7% | August 2016 |
| Electricity consumption | -23.1% | August 2016 |
| Share of 30-minute meetings | +46% | August 2018 |
| Share of remote meetings | +21% | April to June 2019 |
Employee reactions were also favorable. Microsoft reported that 92.1% of surveyed employees approved of the four-day-workweek and three-day-weekend arrangement.
Did Microsoft Japan’s four-day workweek increase productivity by 40%?
The 39.9% increase was a year-over-year change in sales per employee. It was not a controlled measure showing that one less workday caused productivity to rise by exactly that amount.
Microsoft added a clarification on November 8, 2019. It said the figure was factual but resulted from various factors, not only the Work-Life Choice Challenge. That distinction matters because sales can change with demand, contracts, product cycles, staffing, and other business conditions.
The experiment still offers a useful example of how fewer scheduled hours can push an organization to remove inefficient routines. It does not establish a universal productivity gain for every company.
What the experiment can and cannot tell us
The trial shows that Microsoft Japan operated for one month with five additional paid days off while reporting lower resource use and favorable employee feedback. It also shows that shorter meetings and heavier use of digital collaboration tools can accompany a shorter week.
It cannot prove how the same policy would perform over a full year, during a different season, or in companies with different kinds of work. There was no randomized control group, and Microsoft did not isolate the effect of the extra days off from the other changes made at the same time.
Frequently asked questions
Did Microsoft Japan permanently adopt a four-day workweek?
No. The widely reported program was a one-month trial in August 2019, not proof of a permanent company-wide schedule.
Were employees paid for the Fridays off?
Yes. Microsoft said permanent employees received special paid leave on all five Fridays, and the offices closed.
Did productivity really rise by 40%?
Sales per employee rose 39.9% compared with August 2018. Microsoft later clarified that several factors contributed to that result, so it should not be described as a 39.9% gain caused solely by the shorter week.
Did electricity use and printing fall?
Yes. Microsoft reported 23.1% lower electricity consumption and 58.7% fewer printed pages. Both figures were compared with August 2016, not August 2018.
How many employees took part?
Contemporary reporting described Microsoft Japan’s workforce as about 2,300 people. Microsoft’s own results page says the initiative applied company-wide but does not state that headcount in the text of the report.
The takeaway
Microsoft Japan’s 2019 test did not settle the debate over four-day workweeks. It showed that one large office-based company could close every Friday for a month, pay permanent staff as usual, and still report strong business and efficiency measures. The strongest conclusion is modest: time at work and useful output are not the same thing.
When you see a headline claiming that a four-day week “raised productivity by 40%,” check what productivity meant, which period was used for comparison, and whether the organization claimed a causal link. Those details change the story.
For another look at how technology may reshape office work, read our explainer on why local AI on a personal computer matters.
Sources: Microsoft Japan’s official results report and The Guardian’s contemporary report.
